Influence of Sputtering Parameters on the Formation Process of High-Quality and Low-Resistivity HfN Thin Film

Abstract

We have investigated the influence of sputtering parameters such as N2 flow ratio, applied dc power and substrate temperature on the formation process of high-quality and low-resistivity HfN film using an ultrahigh-vacuum sputtering system. The obtained film quality was evaluated using X-ray diffraction, X-ray photoelectron spectroscopy and Auger electron spectroscopy analyses. The resistivity values were measured by a four-point probe method. We found that (111) HfN and (100) HfN films with equivalent resistivity to the bulk value can be grown in a single-oriented state at the substrate temperature of 450°C on (111) Si and (001) Si, respectively. Therefore, it is revealed that impurity-free, high-quality HfN film with high crystallinity and low resistivity can be obtained at relatively low substrate temperatures, if appropriate sputtering conditions are satisfied, using an ultrahigh-vacuum sputtering system.

Mechanisms of Ohmic Contact Formation and Carrier Transport of Low Temperature Annealed Hf/Al/Ta on In0.18Al0.82N/GaN-on-Si

“…• C. [21][22][23] In our case, the possible formation of HfN can be linked with the observed out-diffusion of N, which can be understood as follows. The out diffusion of N at 600…”

TiN/(Al,Sc)N metal/dielectric superlattices and multilayers as hyperbolic metamaterials in the visible spectral range

“…Shinkai et al 27 have demonstrated growth of single-orientation HfN on (001) and (111) Si substrates. Therefore, using HfN as a buffer layer we should be able to deposit epitaxial superlattices on Si substrates.…”

Lattice-matched HfN buffer layers for epitaxy of GaN on Si

“…Due to the small (0.02%) mismatch for the coincident-site lattice involving 6 HfN unit cells and 5 Si unit cells, HfN can be grown epitaxially on Si. 17 Like AlN, HfN is stable with regard 2 to formation of Si 3 N 4 , but should offer better diffusion resistance. Additionally, HfN is expected to form an ohmic contact to n-GaN.…”

“…17 It is emphasized that this process was not originally intended to prepare buffer layers for GaN growth, and the 450°C HfN deposition temperature was the practical maximum for the deposition chamber rather than the optimum for HfN epitaxy. The HfN stoichiometry was confirmed by x-ray photoelectron spectroscopy and the cube-on-cube epitaxial relationship was verified by x-ray diffraction.…”